diff --git a/.github/workflows/lint-scripts/websites-shared-credentials-duplicates.rb b/.github/workflows/lint-scripts/websites-shared-credentials-duplicates.rb
index d97ae3264..b02265a9c 100644
--- a/.github/workflows/lint-scripts/websites-shared-credentials-duplicates.rb
+++ b/.github/workflows/lint-scripts/websites-shared-credentials-duplicates.rb
@@ -1,12 +1,22 @@
 require 'json'
 require 'set'
 
-shared_websites = JSON.parse(File.read('quirks/websites-with-shared-credential-backends.json'))
+KEYS = ["from", "to", "shared"]
+
+shared_credentials = JSON.parse(File.read('quirks/shared-credentials.json'))
+shared_credentials_historical = JSON.parse(File.read('quirks/shared-credentials-historical.json'))
+
+domains = []
+(shared_credentials + shared_credentials_historical).each do |entry|
+  KEYS.each do |key|
+    domains += entry[key] if entry[key]
+  end
+end
 
 seen_domains = Set.new
-shared_websites.flatten.each do |domain|
+domains.each do |domain|
   STDERR.puts "The domain '#{domain}' appears more than once!" if seen_domains.include?(domain)
   seen_domains << domain
 end
 
-exit(1) if seen_domains.count != shared_websites.flatten.count
\ No newline at end of file
+exit(1) if seen_domains.count != domains.count
\ No newline at end of file
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 3bab5c4d0..242cea0fe 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -40,8 +40,6 @@ jobs:
       run: ruby .github/workflows/lint-scripts/websites-shared-credentials-sort-order.rb
     - name: Lint Duplicates
       run: ruby .github/workflows/lint-scripts/websites-shared-credentials-duplicates.rb
-    - name: Verify Generated Files
-      run: ruby tools/convert-shared-credential-to-legacy-format.rb --verify
 
   validate-schemas:
     runs-on: ubuntu-latest
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a276808f3..b9922049a 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -51,8 +51,6 @@ Each entry in [`quirks/shared-credentials.json`](quirks/shared-credentials.json)
 
 When contributing or amending a set of websites sharing a credential backend, you should state why you believe the relevant domains do or do not share a credential backend, with evidence to support your claim. This may involve WHOIS information or content served from the domains themselves.
 
-[`quirks/websites-with-shared-credential-backends.json`](quirks/websites-with-shared-credential-backends.json) contains a lower fidelity version of the data in [`quirks/shared-credentials.json`](quirks/shared-credentials.json) and [`quirks/shared-credentials-historical.json`](quirks/shared-credentials-historical.json). It must be regenerated using [`tools/convert-shared-credential-to-legacy-format.rb`](tools/convert-shared-credential-to-legacy-format.rb) whenever those files are changed. Please do not edit [`quirks/websites-with-shared-credential-backends.json`](quirks/websites-with-shared-credential-backends.json) manually.
-
 ### Contributing a Change Password URL
 
 Use the website in question until you find the standalone page for updating the user's password, or a high-level "Account Information" or "Security" page. The closer the URL takes the user to be able to change their password, the better. Before adding a URL, ensure that it works properly both when the user is logged in and when they are not. URLs added to [`quirks/change-password-URLs.json`](quirks/change-password-URLs.json) should have a scheme of https unless the website does not allow changing the password on an https page.
diff --git a/quirks/schemas/websites-with-shared-credential-backends-schema.json b/quirks/schemas/websites-with-shared-credential-backends-schema.json
deleted file mode 100644
index bc2172f8a..000000000
--- a/quirks/schemas/websites-with-shared-credential-backends-schema.json
+++ /dev/null
@@ -1,12 +0,0 @@
-{
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "type": "array",
-  "items": {
-    "type": "array",
-    "uniqueItems": true,
-    "items": {
-      "type": "string"
-    },
-    "minItems": 1
-  }
-}
diff --git a/quirks/websites-with-shared-credential-backends.json b/quirks/websites-with-shared-credential-backends.json
deleted file mode 100644
index 0a8295b15..000000000
--- a/quirks/websites-with-shared-credential-backends.json
+++ /dev/null
@@ -1,935 +0,0 @@
-[
-    [
-        "3docean.net",
-        "audiojungle.net",
-        "codecanyon.net",
-        "envato.com",
-        "graphicriver.net",
-        "photodune.net",
-        "placeit.net",
-        "themeforest.net",
-        "tutsplus.com",
-        "videohive.net"
-    ],
-    [
-        "aa.com",
-        "americanairlines.com",
-        "americanairlines.jp"
-    ],
-    [
-        "aetna.com",
-        "banneraetna.myplanportal.com"
-    ],
-    [
-        "airbnb.com.ar",
-        "airbnb.com.au",
-        "airbnb.at",
-        "airbnb.be",
-        "airbnb.com.bz",
-        "airbnb.com.bo",
-        "airbnb.com.br",
-        "airbnb.ca",
-        "airbnb.cl",
-        "airbnb.com.co",
-        "airbnb.co.cr",
-        "airbnb.cz",
-        "airbnb.dk",
-        "airbnb.com.ec",
-        "airbnb.com.sv",
-        "airbnb.fi",
-        "airbnb.fr",
-        "airbnb.de",
-        "airbnb.gr",
-        "airbnb.com.gt",
-        "airbnb.gy",
-        "airbnb.com.hn",
-        "airbnb.com.hk",
-        "airbnb.hu",
-        "airbnb.is",
-        "airbnb.co.in",
-        "airbnb.co.id",
-        "airbnb.ie",
-        "airbnb.it",
-        "airbnb.jp",
-        "airbnb.com.my",
-        "airbnb.com.mt",
-        "airbnb.mx",
-        "airbnb.nl",
-        "airbnb.co.nz",
-        "airbnb.com.ni",
-        "airbnb.no",
-        "airbnb.com.pa",
-        "airbnb.com.py",
-        "airbnb.com.pe",
-        "airbnb.pl",
-        "airbnb.pt",
-        "airbnb.ru",
-        "airbnb.com.sg",
-        "airbnb.co.kr",
-        "airbnb.es",
-        "airbnb.se",
-        "airbnb.ch",
-        "airbnb.com.tw",
-        "airbnb.com.tr",
-        "airbnb.co.uk",
-        "airbnb.com",
-        "airbnb.co.ve"
-    ],
-    [
-        "airnewzealand.co.nz",
-        "airnewzealand.com",
-        "airnewzealand.com.au"
-    ],
-    [
-        "albertsons.com",
-        "acmemarkets.com",
-        "carrsqc.com",
-        "jewelosco.com",
-        "pavilions.com",
-        "randalls.com",
-        "safeway.com",
-        "shaws.com",
-        "starmarket.com",
-        "tomthumb.com",
-        "vons.com"
-    ],
-    [
-        "alelo.com.br",
-        "meualelo.com.br"
-    ],
-    [
-        "alibaba.com",
-        "aliexpress.com"
-    ],
-    [
-        "alltrails.com",
-        "alltrails.io"
-    ],
-    [
-        "amazon.com",
-        "amazon.ae",
-        "amazon.com.au",
-        "amazon.com.br",
-        "amazon.ca",
-        "amazon.fr",
-        "amazon.de",
-        "amazon.in",
-        "amazon.it",
-        "amazon.com.mx",
-        "amazon.nl",
-        "amazon.es",
-        "amazon.com.tr",
-        "amazon.co.uk",
-        "amazon.sa",
-        "amazon.sg",
-        "amazon.se",
-        "amazon.pl"
-    ],
-    [
-        "amcrestcloud.com",
-        "amcrestview.com"
-    ],
-    [
-        "americastestkitchen.com",
-        "cooksillustrated.com",
-        "cookscountry.com",
-        "onlinecookingschool.com"
-    ],
-    [
-        "ameritrade.com",
-        "tdameritrade.com"
-    ],
-    [
-        "ana.co.jp",
-        "astyle.jp"
-    ],
-    [
-        "angel.co",
-        "wellfound.com"
-    ],
-    [
-        "anthem.com",
-        "sydneyhealth.com"
-    ],
-    [
-        "anylist.com",
-        "anylistapp.com"
-    ],
-    [
-        "appannie.com",
-        "data.ai"
-    ],
-    [
-        "apple.com",
-        "icloud.com"
-    ],
-    [
-        "atlassian.com",
-        "trello.com"
-    ],
-    [
-        "att.com",
-        "att.net"
-    ],
-    [
-        "audi.com",
-        "audiusa.com"
-    ],
-    [
-        "bahn.de",
-        "bahn.com"
-    ],
-    [
-        "battle.net",
-        "blizzard.com"
-    ],
-    [
-        "beachbodyondemand.com",
-        "teambeachbody.com"
-    ],
-    [
-        "beavercreek.com",
-        "breckenridge.com",
-        "epicpass.com",
-        "keystoneresort.com",
-        "kirkwood.com",
-        "mountsunapee.com",
-        "northstarcalifornia.com",
-        "okemo.com",
-        "parkcitymountain.com",
-        "skicb.com",
-        "skiheavenly.com",
-        "snow.com",
-        "stevenspass.com",
-        "stowe.com",
-        "vail.com",
-        "whistlerblackcomb.com"
-    ],
-    [
-        "bgg.cc",
-        "boardgamegeek.com",
-        "rpggeek.com",
-        "videogamegeek.com"
-    ],
-    [
-        "boingo.com",
-        "boingohotspot.com"
-    ],
-    [
-        "bol.com",
-        "kobo.com"
-    ],
-    [
-        "boudinbakery.com",
-        "boudincatering.com"
-    ],
-    [
-        "braze.com",
-        "braze.eu"
-    ],
-    [
-        "capitalone.com",
-        "capitalone360.com"
-    ],
-    [
-        "cathaypacific.com",
-        "asiamiles.com"
-    ],
-    [
-        "centralfcu.org",
-        "centralfcu.com"
-    ],
-    [
-        "citi.com",
-        "citibank.com",
-        "citibankonline.com"
-    ],
-    [
-        "comcast.net",
-        "xfinity.com"
-    ],
-    [
-        "coolblue.nl",
-        "coolblue.be",
-        "coolblue.de"
-    ],
-    [
-        "curbed.com",
-        "grubstreet.com",
-        "nymag.com",
-        "thecut.com",
-        "vulture.com"
-    ],
-    [
-        "dan.org",
-        "diversalertnetwork.org"
-    ],
-    [
-        "dinersclubnorthamerica.com",
-        "dinersclubus.com"
-    ],
-    [
-        "discordapp.com",
-        "discord.com"
-    ],
-    [
-        "discordmerch.com",
-        "discord.store"
-    ],
-    [
-        "discovercard.com",
-        "discover.com"
-    ],
-    [
-        "dish.com",
-        "mydish.com",
-        "dishnetwork.com"
-    ],
-    [
-        "disney.com",
-        "disneyplus.com",
-        "disneystore.com",
-        "espn.com",
-        "go.com",
-        "hulu.com",
-        "shopdisney.com"
-    ],
-    [
-        "dnt.abine.com",
-        "ironvest.com"
-    ],
-    [
-        "docusign.com",
-        "docusign.net"
-    ],
-    [
-        "drivethrucards.com",
-        "drivethrucomics.com",
-        "drivethrufiction.com",
-        "drivethrurpg.com",
-        "dmsguild.com",
-        "pathfinderinfinite.com",
-        "storytellersvault.com",
-        "wargamevault.com"
-    ],
-    [
-        "dropbox.com",
-        "getdropbox.com"
-    ],
-    [
-        "eater.com",
-        "polygon.com",
-        "sbnation.com",
-        "theverge.com"
-    ],
-    [
-        "ebay.at",
-        "ebay.be",
-        "ebay.ca",
-        "ebay.ch",
-        "ebay.cn",
-        "ebay.co.th",
-        "ebay.co.uk",
-        "ebay.com",
-        "ebay.com.au",
-        "ebay.com.hk",
-        "ebay.com.my",
-        "ebay.com.sg",
-        "ebay.com.tw",
-        "ebay.de",
-        "ebay.es",
-        "ebay.fr",
-        "ebay.ie",
-        "ebay.it",
-        "ebay.nl",
-        "ebay.ph",
-        "ebay.pl",
-        "ebay.vn"
-    ],
-    [
-        "epicgames.com",
-        "unrealengine.com"
-    ],
-    [
-        "eurosport.no",
-        "eurosportplayer.com"
-    ],
-    [
-        "eventbrite.at",
-        "eventbrite.be",
-        "eventbrite.ca",
-        "eventbrite.ch",
-        "eventbrite.cl",
-        "eventbrite.co",
-        "eventbrite.com",
-        "eventbrite.de",
-        "eventbrite.dk",
-        "eventbrite.es",
-        "eventbrite.fi",
-        "eventbrite.fr",
-        "eventbrite.hk",
-        "eventbrite.ie",
-        "eventbrite.in",
-        "eventbrite.it",
-        "eventbrite.my",
-        "eventbrite.nl",
-        "eventbrite.ph",
-        "eventbrite.pt",
-        "eventbrite.se",
-        "eventbrite.sg"
-    ],
-    [
-        "facebook.com",
-        "messenger.com"
-    ],
-    [
-        "fancourier.ro",
-        "selfawb.ro"
-    ],
-    [
-        "fandangonow.com",
-        "fandango.com"
-    ],
-    [
-        "fidelity.com",
-        "fidelityinvestments.com"
-    ],
-    [
-        "flyblade.com",
-        "blade.com"
-    ],
-    [
-        "flyingblue.com",
-        "klm.com"
-    ],
-    [
-        "fnac.com",
-        "fnacspectacles.com"
-    ],
-    [
-        "fourleaf.net",
-        "fourleaf.cl"
-    ],
-    [
-        "foursquare.com",
-        "swarmapp.com"
-    ],
-    [
-        "gazduire.com.ro",
-        "gazduire.net",
-        "admin.ro"
-    ],
-    [
-        "glassdoor.ca",
-        "glassdoor.com",
-        "glassdoor.com.ar"
-    ],
-    [
-        "gogoair.com",
-        "gogoinflight.com"
-    ],
-    [
-        "hbo.com",
-        "hbomax.com",
-        "hbonow.com",
-        "max.com"
-    ],
-    [
-        "heroku.com",
-        "verify.salesforce.com"
-    ],
-    [
-        "igen.fr",
-        "watchgeneration.fr",
-        "macg.co"
-    ],
-    [
-        "ikonpass.com",
-        "skilynx.com"
-    ],
-    [
-        "ing.de",
-        "ing.com"
-    ],
-    [
-        "instagram.com",
-        "threads.net"
-    ],
-    [
-        "intuit.com",
-        "mint.com"
-    ],
-    [
-        "kaiserpermanente.org",
-        "kp.org"
-    ],
-    [
-        "kclibrary.overdrive.com",
-        "kclibrary.bibliocommons.com"
-    ],
-    [
-        "kcls.bibliocommons.com",
-        "kcls.overdrive.com",
-        "kcls.org"
-    ],
-    [
-        "letsdeel.com",
-        "deel.com"
-    ],
-    [
-        "liebherr.com",
-        "myliebherr.com"
-    ],
-    [
-        "login.airfrance.com",
-        "login.flyingblue.com",
-        "login.klm.com"
-    ],
-    [
-        "logitech.com",
-        "logitechg.com",
-        "logi.com",
-        "astrogaming.com",
-        "ultimateears.com"
-    ],
-    [
-        "lookmark.io",
-        "lookmark.link"
-    ],
-    [
-        "lrz.de",
-        "mwn.de",
-        "mytum.de",
-        "tum.de",
-        "tum.edu"
-    ],
-    [
-        "lufthansa.com",
-        "miles-and-more.com"
-    ],
-    [
-        "marriott.com",
-        "marriottrewards.com",
-        "ritzcarlton.com",
-        "spg.com",
-        "starwoodhotels.com"
-    ],
-    [
-        "mercadolibre.cl",
-        "mercadolibre.co.cr",
-        "mercadolibre.com.ar",
-        "mercadolibre.com.bo",
-        "mercadolibre.com.co",
-        "mercadolibre.com.do",
-        "mercadolibre.com.ec",
-        "mercadolibre.com.gt",
-        "mercadolibre.com.hn",
-        "mercadolibre.com.mx",
-        "mercadolibre.com.ni",
-        "mercadolibre.com.pa",
-        "mercadolibre.com.pe",
-        "mercadolibre.com.py",
-        "mercadolibre.com.sv",
-        "mercadolibre.com.uy",
-        "mercadolibre.com.ve",
-        "mercadopago.cl",
-        "mercadopago.com.ar",
-        "mercadopago.com.co",
-        "mercadopago.com.ec",
-        "mercadopago.com.mx",
-        "mercadopago.com.pe",
-        "mercadopago.com.uy",
-        "mercadopago.com.ve",
-        "mercadolibre.com"
-    ],
-    [
-        "mercadolivre.com.br",
-        "mercadopago.com.br",
-        "mercadolivre.com"
-    ],
-    [
-        "microsoft.com",
-        "live.com",
-        "microsoftonline.com",
-        "office.com",
-        "skype.com",
-        "onenote.com",
-        "hotmail.com",
-        "azure.com"
-    ],
-    [
-        "minecraft.net",
-        "mojang.com"
-    ],
-    [
-        "moneybird.nl",
-        "moneybird.de",
-        "moneybird.com"
-    ],
-    [
-        "mytotalconnectcomfort.com",
-        "tccna.honeywell.com"
-    ],
-    [
-        "myuhc.com",
-        "uhc.com",
-        "optum.com",
-        "optumrx.com"
-    ],
-    [
-        "neatorama.com",
-        "neatoshop.com"
-    ],
-    [
-        "nebula.app",
-        "watchnebula.com",
-        "nebula.tv"
-    ],
-    [
-        "newyorker.com",
-        "vanityfair.com"
-    ],
-    [
-        "nextinpact.com",
-        "next.ink"
-    ],
-    [
-        "nintendolife.com",
-        "purexbox.com",
-        "pushsquare.com"
-    ],
-    [
-        "nokia.com",
-        "alcatel-lucent.com",
-        "nsn-rdnet.net",
-        "nsn.com"
-    ],
-    [
-        "nordvpn.com",
-        "nordpass.com",
-        "nordaccount.com"
-    ],
-    [
-        "norwegian.com",
-        "norwegianreward.com"
-    ],
-    [
-        "olo.com",
-        "olo.express"
-    ],
-    [
-        "overstock.com",
-        "bedbathandbeyond.com"
-    ],
-    [
-        "parkmobile.us",
-        "parkmobile.io"
-    ],
-    [
-        "pinterest.com",
-        "pinterest.ca",
-        "pinterest.co.uk",
-        "pinterest.fr",
-        "pinterest.de",
-        "pinterest.es",
-        "pinterest.com.au",
-        "pinterest.se",
-        "pinterest.ph",
-        "pinterest.ch",
-        "pinterest.com.mx",
-        "pinterest.dk",
-        "pinterest.pt",
-        "pinterest.ru",
-        "pinterest.it",
-        "pinterest.at",
-        "pinterest.jp",
-        "pinterest.cl",
-        "pinterest.ie",
-        "pinterest.co.kr",
-        "pinterest.nz"
-    ],
-    [
-        "pocket.com",
-        "getpocket.com"
-    ],
-    [
-        "postnl.nl",
-        "postnl.be"
-    ],
-    [
-        "pretendo.network",
-        "pretendo.cc"
-    ],
-    [
-        "probikeshop.fr",
-        "bikeshop.es",
-        "probikeshop.it",
-        "probikeshop.pt",
-        "probikeshop.com"
-    ],
-    [
-        "proton.me",
-        "protonvpn.com",
-        "protonmail.ch",
-        "protonmail.com"
-    ],
-    [
-        "qnap.com",
-        "myqnapcloud.com"
-    ],
-    [
-        "questdiagnostics.com",
-        "care360.com"
-    ],
-    [
-        "quicken.com",
-        "simplifimoney.com"
-    ],
-    [
-        "raywenderlich.com",
-        "kodeco.com"
-    ],
-    [
-        "redis.com",
-        "redislabs.com"
-    ],
-    [
-        "rocketaccount.com",
-        "rocketmortgage.com"
-    ],
-    [
-        "s.activision.com",
-        "profile.callofduty.com"
-    ],
-    [
-        "scholarshare529.com",
-        "secureaccountview.com"
-    ],
-    [
-        "scottscheapflights.com",
-        "going.com"
-    ],
-    [
-        "scoutingevent.com",
-        "campreservation.com"
-    ],
-    [
-        "scribbr.com",
-        "scribbr.de",
-        "scribbr.dk",
-        "scribbr.es",
-        "scribbr.fi",
-        "scribbr.fr",
-        "scribbr.it",
-        "scribbr.nl",
-        "scribbr.no",
-        "scribbr.se"
-    ],
-    [
-        "seattle.bibliocommons.com",
-        "spl.overdrive.com",
-        "spl.org"
-    ],
-    [
-        "sfpl.bibliocommons.com",
-        "sfpl.overdrive.com"
-    ],
-    [
-        "slcl.overdrive.com",
-        "slcl.org"
-    ],
-    [
-        "slpl.bibliocommons.com",
-        "slpl.overdrive.com"
-    ],
-    [
-        "sonyentertainmentnetwork.com",
-        "sony.com"
-    ],
-    [
-        "spark.net",
-        "jdate.com"
-    ],
-    [
-        "spirit.com",
-        "spirit-airlines.com"
-    ],
-    [
-        "springfield.overdrive.com",
-        "coolcat.org"
-    ],
-    [
-        "square.com",
-        "squareup.com"
-    ],
-    [
-        "stackoverflow.com",
-        "askubuntu.com",
-        "serverfault.com",
-        "stackexchange.com",
-        "superuser.com"
-    ],
-    [
-        "steampowered.com",
-        "steamcommunity.com"
-    ],
-    [
-        "taxhawk.com",
-        "freetaxusa.com",
-        "express1040.com"
-    ],
-    [
-        "telegram.me",
-        "telegram.org"
-    ],
-    [
-        "telekom-dienste.de",
-        "accounts.login.idm.telekom.com"
-    ],
-    [
-        "tesla.com",
-        "teslamotors.com"
-    ],
-    [
-        "ticketmaster.com",
-        "livenation.com"
-    ],
-    [
-        "ting.com",
-        "tingmobile.com"
-    ],
-    [
-        "tp-link.com",
-        "tplinkcloud.com"
-    ],
-    [
-        "transferwise.com",
-        "wise.com"
-    ],
-    [
-        "turkishairlines.com",
-        "thy.com"
-    ],
-    [
-        "tvnow.de",
-        "tvnow.at",
-        "tvnow.ch",
-        "auth.rtl.de",
-        "rtlplus.de",
-        "rtlplus.com"
-    ],
-    [
-        "twitter.com",
-        "x.com"
-    ],
-    [
-        "ubi.com",
-        "ubisoft.com"
-    ],
-    [
-        "umsystem.edu",
-        "mst.edu",
-        "umkc.edu",
-        "umsl.edu",
-        "missouri.edu"
-    ],
-    [
-        "united.com",
-        "unitedwifi.com"
-    ],
-    [
-        "uspowerboating.com",
-        "ussailing.org"
-    ],
-    [
-        "verizon.com",
-        "verizonwireless.com",
-        "vzw.com"
-    ],
-    [
-        "wacom.eu",
-        "wacom.com"
-    ],
-    [
-        "wayfair.com",
-        "wayfair.ca",
-        "jossandmain.com",
-        "allmodern.com",
-        "perigold.com",
-        "birchlane.com"
-    ],
-    [
-        "wellsfargo.com",
-        "wellsfargoadvisors.com"
-    ],
-    [
-        "wiimmfi.de",
-        "wii-homebrew.com"
-    ],
-    [
-        "wikipedia.org",
-        "mediawiki.org",
-        "wikibooks.org",
-        "wikidata.org",
-        "wikinews.org",
-        "wikiquote.org",
-        "wikisource.org",
-        "wikiversity.org",
-        "wikivoyage.org",
-        "wiktionary.org",
-        "commons.wikimedia.org",
-        "meta.wikimedia.org",
-        "incubator.wikimedia.org",
-        "outreach.wikimedia.org",
-        "species.wikimedia.org",
-        "wikimania.wikimedia.org"
-    ],
-    [
-        "williams-sonoma.com",
-        "markandgraham.com",
-        "potterybarn.com",
-        "westelm.com"
-    ],
-    [
-        "wilson.com",
-        "slugger.com",
-        "atecsports.com",
-        "demarini.com",
-        "evoshield.com",
-        "luxilon.com"
-    ],
-    [
-        "worldlink.com.np",
-        "nettv.com.np"
-    ],
-    [
-        "wsj.com",
-        "dowjones.com"
-    ],
-    [
-        "www.seek.com.au",
-        "www.seek.co.nz",
-        "jobsdb.com",
-        "hk.jobsdb.com",
-        "sg.jobsdb.com",
-        "th.jobsdb.com",
-        "jobstreet.com",
-        "myjobstreet.jobstreet.co.id",
-        "myjobstreet.jobstreet.com.my",
-        "myjobstreet.jobstreet.com.ph",
-        "myjobstreet.jobstreet.com.sg",
-        "login.seek.com"
-    ],
-    [
-        "www.vistaprint.ca",
-        "account.vistaprint.com"
-    ],
-    [
-        "youneedabudget.com",
-        "ynab.com"
-    ],
-    [
-        "zixmail.net",
-        "zixmessagecenter.com"
-    ]
-]
diff --git a/tools/convert-shared-credential-to-legacy-format.rb b/tools/convert-shared-credential-to-legacy-format.rb
index 955df191f..9c149e241 100755
--- a/tools/convert-shared-credential-to-legacy-format.rb
+++ b/tools/convert-shared-credential-to-legacy-format.rb
@@ -3,11 +3,22 @@
 require 'json'
 require 'optparse'
 
+name_of_script = File.basename $0
+BANNER = "Usage: #{name_of_script} [options] <output file path>"
+USAGE_MESSAGE = <<-END
+This script converts shared-credentials.json and shared-credentials-historical.json into the legacy
+format (previously contained in websites-with-shared-credential-backends.json).
+END
+
 options = {}
-OptionParser.new do |opts|
-  opts.on("--verify", "Verify that the generated file is up-to-date.") do |v|
+option_parser = OptionParser.new(BANNER, 25) do |parser|
+  parser.on("--verify", "Verify that the generated file is up-to-date.") do |v|
     options[:verify] = v
   end
+  parser.on_tail("-h", "--help", 'Show this message') do
+    puts parser, "", USAGE_MESSAGE
+    exit
+  end
 end.parse!
 
 tools_dir = __dir__
@@ -16,7 +27,12 @@
 
 shared_credentials_file_path = File.join quirks_dir, "shared-credentials.json"
 shared_credentials_historical_file_path = File.join quirks_dir, "shared-credentials-historical.json"
-output_file_path = File.join quirks_dir, "websites-with-shared-credential-backends.json"
+
+output_file_path = ARGV.shift
+if !output_file_path
+  puts BANNER
+  exit 1
+end
 
 legacy_output_array = []
 
@@ -49,7 +65,7 @@ def addEntriesToLegacyOutputArray(file_path, legacy_output_array)
 if options[:verify]
   current_file_contents = File.read output_file_path
   if current_file_contents != json_to_output
-    STDERR.puts "ERROR: #{File.basename output_file_path} is not up-to-date. Please run this script again and commit the changes."
+    STDERR.puts "ERROR: #{File.basename output_file_path} is not up-to-date."
     exit 1
   end
 else